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package javax.imageio.event;

import java.util.EventListener;
import javax.imageio.ImageReader;


An interface used by ImageReader implementations to
notify callers of their image and thumbnail reading methods of
progress.

 This interface receives general indications of decoding
progress (via the imageProgress and
thumbnailProgress methods), and events indicating when
an entire image has been updated (via the
imageStarted, imageComplete,
thumbnailStarted and thumbnailComplete
methods).  Applications that wish to be informed of pixel updates
as they happen (for example, during progressive decoding), should
provide an IIOReadUpdateListener.

See Also:
/**
 * An interface used by <code>ImageReader</code> implementations to
 * notify callers of their image and thumbnail reading methods of
 * progress.
 *
 * <p> This interface receives general indications of decoding
 * progress (via the <code>imageProgress</code> and
 * <code>thumbnailProgress</code> methods), and events indicating when
 * an entire image has been updated (via the
 * <code>imageStarted</code>, <code>imageComplete</code>,
 * <code>thumbnailStarted</code> and <code>thumbnailComplete</code>
 * methods).  Applications that wish to be informed of pixel updates
 * as they happen (for example, during progressive decoding), should
 * provide an <code>IIOReadUpdateListener</code>.
 *
 * @see IIOReadUpdateListener
 * @see javax.imageio.ImageReader#addIIOReadProgressListener
 * @see javax.imageio.ImageReader#removeIIOReadProgressListener
 *
 */
public interface IIOReadProgressListener extends EventListener {

    
Reports that a sequence of read operations is beginning.
ImageReader implementations are required to call
this method exactly once from their
readAll(Iterator) method.

Params:
  • source – the ImageReader object calling this method.
  • minIndex – the index of the first image to be read.
/**
     * Reports that a sequence of read operations is beginning.
     * <code>ImageReader</code> implementations are required to call
     * this method exactly once from their
     * <code>readAll(Iterator)</code> method.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param minIndex the index of the first image to be read.
     */
    void sequenceStarted(ImageReader source, int minIndex);

    
Reports that a sequence of read operations has completed.
ImageReader implementations are required to call
this method exactly once from their
readAll(Iterator) method.

Params:
  • source – the ImageReader object calling this method.
/**
     * Reports that a sequence of read operations has completed.
     * <code>ImageReader</code> implementations are required to call
     * this method exactly once from their
     * <code>readAll(Iterator)</code> method.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     */
    void sequenceComplete(ImageReader source);

    
Reports that an image read operation is beginning.  All
ImageReader implementations are required to call
this method exactly once when beginning an image read
operation.

Params:
  • source – the ImageReader object calling this method.
  • imageIndex – the index of the image being read within its
containing input file or stream.
/**
     * Reports that an image read operation is beginning.  All
     * <code>ImageReader</code> implementations are required to call
     * this method exactly once when beginning an image read
     * operation.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param imageIndex the index of the image being read within its
     * containing input file or stream.
     */
    void imageStarted(ImageReader source, int imageIndex);

    
Reports the approximate degree of completion of the current
read call of the associated
ImageReader.

 The degree of completion is expressed as a percentage
varying from 0.0F to 100.0F.  The
percentage should ideally be calculated in terms of the
remaining time to completion, but it is usually more practical
to use a more well-defined metric such as pixels decoded or
portion of input stream consumed.  In any case, a sequence of
calls to this method during a given read operation should
supply a monotonically increasing sequence of percentage
values.  It is not necessary to supply the exact values
0 and 100, as these may be inferred
by the callee from other methods.

 Each particular ImageReader implementation may
call this method at whatever frequency it desires.  A rule of
thumb is to call it around each 5 percent mark.

Params:
  • source – the ImageReader object calling this method.
  • percentageDone – the approximate percentage of decoding that
has been completed.
/**
     * Reports the approximate degree of completion of the current
     * <code>read</code> call of the associated
     * <code>ImageReader</code>.
     *
     * <p> The degree of completion is expressed as a percentage
     * varying from <code>0.0F</code> to <code>100.0F</code>.  The
     * percentage should ideally be calculated in terms of the
     * remaining time to completion, but it is usually more practical
     * to use a more well-defined metric such as pixels decoded or
     * portion of input stream consumed.  In any case, a sequence of
     * calls to this method during a given read operation should
     * supply a monotonically increasing sequence of percentage
     * values.  It is not necessary to supply the exact values
     * <code>0</code> and <code>100</code>, as these may be inferred
     * by the callee from other methods.
     *
     * <p> Each particular <code>ImageReader</code> implementation may
     * call this method at whatever frequency it desires.  A rule of
     * thumb is to call it around each 5 percent mark.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param percentageDone the approximate percentage of decoding that
     * has been completed.
     */
    void imageProgress(ImageReader source, float percentageDone);

    
Reports that the current image read operation has completed.
All ImageReader implementations are required to
call this method exactly once upon completion of each image
read operation.

Params:
  • source – the ImageReader object calling this
method.
/**
     * Reports that the current image read operation has completed.
     * All <code>ImageReader</code> implementations are required to
     * call this method exactly once upon completion of each image
     * read operation.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     */
    void imageComplete(ImageReader source);

    
Reports that a thumbnail read operation is beginning.  All
ImageReader implementations are required to call
this method exactly once when beginning a thumbnail read
operation.

Params:
  • source – the ImageReader object calling this method.
  • imageIndex – the index of the image being read within its
containing input file or stream.
  • thumbnailIndex – the index of the thumbnail being read.
/**
     * Reports that a thumbnail read operation is beginning.  All
     * <code>ImageReader</code> implementations are required to call
     * this method exactly once when beginning a thumbnail read
     * operation.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param imageIndex the index of the image being read within its
     * containing input file or stream.
     * @param thumbnailIndex the index of the thumbnail being read.
     */
    void thumbnailStarted(ImageReader source,
                          int imageIndex, int thumbnailIndex);

    
Reports the approximate degree of completion of the current
getThumbnail call within the associated
ImageReader.  The semantics are identical to those
of imageProgress.

Params:
  • source – the ImageReader object calling this method.
  • percentageDone – the approximate percentage of decoding that
has been completed.
/**
     * Reports the approximate degree of completion of the current
     * <code>getThumbnail</code> call within the associated
     * <code>ImageReader</code>.  The semantics are identical to those
     * of <code>imageProgress</code>.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param percentageDone the approximate percentage of decoding that
     * has been completed.
     */
    void thumbnailProgress(ImageReader source, float percentageDone);

    
Reports that a thumbnail read operation has completed.  All
ImageReader implementations are required to call
this method exactly once upon completion of each thumbnail read
operation.

Params:
  • source – the ImageReader object calling this
method.
/**
     * Reports that a thumbnail read operation has completed.  All
     * <code>ImageReader</code> implementations are required to call
     * this method exactly once upon completion of each thumbnail read
     * operation.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     */
    void thumbnailComplete(ImageReader source);

    
Reports that a read has been aborted via the reader's
abort method.  No further notifications will be
given.

Params:
  • source – the ImageReader object calling this
method.
/**
     * Reports that a read has been aborted via the reader's
     * <code>abort</code> method.  No further notifications will be
     * given.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     */
    void readAborted(ImageReader source);
}